update

GinRateLimit.go

@@ -31,7 +31,7 @@ type InMemoryStoreType struct {
 	mutex *sync.Mutex
 }
 
-func (s *InMemoryStoreType) Limit(key string) bool {
+func (s *InMemoryStoreType) Limit(key string) (bool, time.Duration) {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 	_, ok := s.data[key]
@@ -42,17 +42,18 @@ func (s *InMemoryStoreType) Limit(key string) bool {
 	if u.ts+s.rate <= time.Now().Unix() {
 		u.tokens = s.limit
 	}
+	remaining := time.Duration((s.rate - (time.Now().Unix() - u.ts)) * time.Second.Nanoseconds())
 	if u.tokens <= 0 {
-		return true
+		return true, remaining
 	}
 	u.tokens--
 	u.ts = time.Now().Unix()
 	s.data[key] = u
-	return false
+	return false, time.Duration(0)
 }
 
 type store interface {
-	Limit(key string) bool
+	Limit(key string) (bool, time.Duration)
 }
 
 func InMemoryStore(rate time.Duration, limit int) *InMemoryStoreType {
@@ -63,12 +64,12 @@ func InMemoryStore(rate time.Duration, limit int) *InMemoryStoreType {
 	return &store
 }
 
-func RateLimiter(keyFunc func(c *gin.Context) string, errorHandler func(c *gin.Context), s store) func(ctx *gin.Context) {
+func RateLimiter(keyFunc func(c *gin.Context) string, errorHandler func(c *gin.Context, remaining time.Duration), s store) func(ctx *gin.Context) {
 	return func(c *gin.Context) {
 		key := keyFunc(c)
-		limited := s.Limit(key)
+		limited, remaining := s.Limit(key)
 		if limited {
-			errorHandler(c)
+			errorHandler(c, remaining)
 			c.Abort()
 		} else {
 			c.Next()

README.md

@@ -33,8 +33,8 @@ func keyFunc(c *gin.Context) string {
 	return c.ClientIP()
 }
 
-func errorHandler(c *gin.Context) {
-	c.String(429, "Too many requests")
+func errorHandler(c *gin.Context, remaining time.Duration) {
+	c.String(429, "Too many requests. Try again in "+remaining.String())
 }
 
 func main() {
@@ -71,8 +71,8 @@ func keyFunc(c *gin.Context) string {
 	return c.ClientIP()
 }
 
-func errorHandler(c *gin.Context) {
-	c.String(429, "Too many requests")
+func errorHandler(c *gin.Context, remaining time.Duration) {
+	c.String(429, "Too many requests. Try again in "+remaining.String())
 }
 
 func main() {
@@ -94,12 +94,15 @@ Custom Store Example
 ```go
 package main
 
+import "time"
+
 type CustomStore struct {
 }
 
 // Your store must have a method called Limit that takes a key and returns a bool
-func (s *CustomStore) Limit(key string) bool {
+func (s *CustomStore) Limit(key string) (bool, time.Duration) {
 	// Do your rate limit logic, and return true if the user went over the rate limit, otherwise return false
+	// Return the amount of time the client needs to wait to make a new request
 	if UserWentOverLimit {
 		return true
 	}

go.mod

@@ -1,28 +1,34 @@
 module github.com/JGLTechnologies/GinRateLimit
 
-go 1.17
+go 1.18
 
 require (
-	github.com/gin-gonic/gin v1.7.7
-	github.com/go-redis/redis/v8 v8.11.4
+	github.com/gin-gonic/gin v1.8.1
+	github.com/go-redis/redis/v8 v8.11.5
+)
+
+require (
+	github.com/goccy/go-json v0.9.7 // indirect
+	github.com/pelletier/go-toml/v2 v2.0.1 // indirect
+	golang.org/x/net v0.0.0-20210428140749-89ef3d95e781 // indirect
+	golang.org/x/text v0.3.6 // indirect
 )
 
 require (
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
-	github.com/go-playground/locales v0.13.0 // indirect
-	github.com/go-playground/universal-translator v0.17.0 // indirect
-	github.com/go-playground/validator/v10 v10.4.1 // indirect
-	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/json-iterator/go v1.1.9 // indirect
-	github.com/leodido/go-urn v1.2.0 // indirect
-	github.com/mattn/go-isatty v0.0.12 // indirect
+	github.com/go-playground/locales v0.14.0 // indirect
+	github.com/go-playground/universal-translator v0.18.0 // indirect
+	github.com/go-playground/validator/v10 v10.10.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/leodido/go-urn v1.2.1 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 // indirect
-	github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 // indirect
-	github.com/ugorji/go/codec v1.1.7 // indirect
-	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 // indirect
-	golang.org/x/sys v0.0.0-20210423082822-04245dca01da // indirect
-	google.golang.org/protobuf v1.26.0 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect; indirec
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/ugorji/go/codec v1.2.7 // indirect
+	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
+	golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e // indirect
+	google.golang.org/protobuf v1.28.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
 )